Electrical high-vacuum discharge tube



Dec. 29, 1953 Filed July 23, 1951 fizardj uaer Patented Dec. 29,1953

2,664,516 ELECTRICAL HIGH-VACUUM DISCHARGE TUBE Theodor Zimmer andEckhard Fenner, Erlangen, Germany Application July 23, 1951, Serial No.238,114

Claims priority, application Germany August 19, 1950 This invention isconcerned with an electrical high-vacuum discharge tube having at leastone large electrode which is secured to the tube en velope, especiallythe anode of a rotary anode X-ray tube, and has particularly to do withthe mounting or securing of such an electrode.

A drawback arises in the manufacture of such tubes, due to the fact thatthe electrode, which is prior to the assembly in the tube cleaned anddegassed by heating in a vacuum or in a neutral gas, is again heatedincident to fusing it to the glass envelope of the tube. The electrodeoxidizes incident to this reheating and again takes up gases from theair. These gases escape from the metallic parts in the presence of thehigh temperatures occurring during the operation of the tube, andtherefore have a detrimental effect on the vacuum thereof.

The invention avoids these drawbacks by the provision of a preferablypot-shaped securing or mounting member which is fused to the tubeenvelope and to which the metallic electrode can be fastened by screw,clamp or bayonet joint means or the like without necessitating heatingthereof.

The potlike member may be made of metal and seals one end of the tubularglass wall of the envelope. It can thus easily be cleaned and againdegassed after fusing to the envelope glass wall. An auxiliary glasscylinder may be introduced into the corresponding tubular glassextension of the tube envelope during such repeated degassing of thepotlike member, for catching and conducting to the outside the liberatedgases, thereby avoiding detrimental effects on the inner wall of theglass extension. The metallic electrode (rotary anode), which has beenseparately degassed, can then be directly fastened, without heating, tothe potlike member which has been fused to the envelope extension.

Tubes made in accordance with the invention, as indicated above, secureto a very high degree the maintenance of the high vacuum during theoperation thereof.

The objects noted above and other objects and features will appear moreclearly from the description which is rendered below with reference tothe accompanying drawings. In these drawings,

Fig. 1 shows in diagrammatic, partly elevational and partly sectionalrepresentation an ex ample of a rotary anode X-ray tube embodying thefeatures of the invention; and

Fig. 2 illustrates in similar representation another example of theinvention.

- anode extension !2 10 Claims. (01. 213-149) The stator of the rotaryanode system has been omitted from the drawings in order to keep themsimple.

Referring now to the drawings, numeral l indicates in both embodimentsthe cathode sys tem which may be suitably secured to the reentrantenvelope portion 2. The rotor of the rotary anode system comprises thecopper cylinder 3 from which extends the pin 4 carrying the anode disk5. The copper cylinder is, by means of the iron cylinder 6 (Fig. 1),supported on the journal (not shown) of the rotor carrier. In Fig. 1this rotor carrier is the metal tube '2, and in Fig. 2 it is themetallic member l3 having a boltlike threaded extension l4 and a flangeis.

The rotor carrier 1 is in Fig. 1 secured in the potlike metallicmounting or securing member 9,, and in Fig. 2 it is secured in thepotlike member i5, These potlike members are in each case in vacuumtightmanner connected with the of the glass envelope by means of the metallicring H which is fused to the envelope extension wall.

In the embodiment shown in Fig. 1, the rotor carrier 1 is fastened orclamped in the metallic pot by the annular groove 8 formed by the potwall portion it. In the embodiment shown in Fig. 2, there is provided onthe rotor carrier l3 the threaded boltlike extension M which is inthreaded engagement with the inside of the metallic pot 15.

The rotor and rotor carrier form in both embodiments a unit which is,prior to mounting in the tube, cleaned and degassed and is thenmechanically secured in position without heating, by attachment to thecorresponding potlike securing and sealing member which is fused to theenvelope wall of the tube, as described.

The copper cylinder 3 of the structure shown in Fig. 2 is provided witha bore ll through which a suitable key tool is inserted incident toscrewing the rotor carrier l3 into the pot [5, the key engaging a boreor depression in the carrier I3, whereby the rotor is temporarilycoupled with its carrier so that the screwing of the extension i l intothe pot 55 can be accomplished by rotation of the rotor. The rotorcarrier I3 is in mounted position secured against angular displacement,by means of the stud screw l8 which engages the carrier flange 18. Thescrew I6 is accessible through the pump extension l9.

Mechanical clamping engagement of the tubular rotor carrier 1 with thepotlike sealing and securing member 9 (Fig. 1) and threaded engagementof the boltlike extension 14 of the seems l3 with the potlike sealingand securing member l5 (Fig. 2) have been shown and described to giveexamples. It is understood that other equivalent means may be employedsuch, for example, as bayonet joint means or the like, to accomplish thecorresponding connection.

Changes may be made within the spirit of the appended claims.

We claim:

1. Electrical high-vacuum discharge tube having an envelope and a rotaryelectrode forming a unit including a rotor and a carrier for said rotor,and a device for disposing said electrode unit in said tube, said devicecomprising a mounting member extending from said carrier, a potlikereceiving member which is bonded to said envelope at one end thereofprior to disposing said electrode unit therein, said potlike receivingmember forming part of the envelope wall at the corresponding endthereof and forming a recess for receiving said mounting memher, andmeans for mechanically fixedly securing said mounting member in itsposition in said potlike receiving member.

2. The structure as set forth in claim 1, wherein said last-named meanscomprises a thread carried by said mounting member for threadedengagement with said recess in said potlike receiving member.

3. The structure as set forth in claim 1, wherein said last-named meanscomprises an annular groove in said mounting engagement with acorresponding groove in said potlike receiving member.

4. v The structure as set forth in claim 1, where in said mountingmember is a tubular member for insertion into the recess in said potlikere ceiving member.

5. The structure as set forth in claim 1, wherein said mounting memberis a threaded boltlike member for threaded engagement with the recess insaid potlike receiving member.

6. The structure as set forth in claim 1, wherein said potlike receivingmember is a metallic rotor carrier scope and member carrying an annularradially extending flange, said flange being bonded to said envelope. 7.The structure as set forth in claim 1, commember for clamping prising afirst radial flange extending from said mounting member, a second radialfiange extending from said potlike receiving member for abutment withsaid first flange, and means for securing said flange in relativelyfixed engage ment to prevent angular displacement of said mountingmember relative to said potlike receiving member.

8. The structure as set forth in claim 1, wherein said mounting memberis a threaded boltlilre element extending axially from said rotorcarrier for threaded engagement with the recess in said potlikereceiving member, an aperture being formed in said rotor for projectinga tool therethrough, during the assembly of said mounting member withsaid potlike receiving member, for engagement with a recess formedinsaid mounting member, to facilitate threading of said boltlikemounting member into said potlike receiving member.

9. The structure as set forth in claim 1, wherein said potlike receivingmember is a tubular metallic member bonded to the envelope of said tubeat the corresponding end thereof and extending axially therefrom, atubular extension projecting from said carrier axially thereofconstituting said mounting member, said extension being received in saidpotlike receiving member and being fastened therein in clampingengagement therewith.

10. The structure as set forth in claim 9, wherein said tubularextension forming said mounting member is fastened in said receivingmember by ann'ularly inwardly constricting the wall of said receivingmember for engagement with an annular groove formed in the wall of saidtubular mounting member.

THEODOR ZIMMER. ECKHARD FENNER.

References Qited in the file of this patent UNITED STATES PATENTS NumberName Date 1,643,453 Holst Sept. 27, 1927 2,230,857 Atlee Feb. 4, 19412,274,865 Machlett Mar. 3, 1942 2,298,335 Atlee Oct. 13, 1942 2,427,203Essig Sept. 9, 1947

